Which US Airlines Operate The Largest Fleets?

The United States is home to some of the largest airlines by fleet size. With four airlines crossing 700 aircraft each, the market is huge. And, routinely, some of the largest airlines in the world by passenger count are also found in the United States.

The market also shows no signs of slowing down. Aggressive fleet renewal and expansion plans will ensure that U.S. carriers remain on the list of the world’s largest airlines by fleet. This, in spite of some carrier’s ambitions to have a fleet size in the thousands.

Which US Airlines Operate The Largest Fleets?
American is the largest carrier in the United States by fleet size. Photo: Tom Boon/Simple Flying

The list

Airfleets records the following data for fleet size:

  1. American Airlines: 967 aircraft
  2. Delta Air Lines: 914 aircraft
  3. United Airlines: 776 Aircraft
  4. Southwest Airlines: 754 aircraft
  5. SkyWest USA: 518 aircraft
  6. FedEx Express: 416 aircraft
  7. JetBlue Airways: 254 aircraft
  8. UPS: 253 aircraft
  9. Alaska Airlines: 238 aircraft
  10. Republic Airways: 191 aircraft
  11. Envoy Air: 189 aircraft
  12. Endeavor Air: 168 aircraft
  13. Mesa Airlines: 145 aircraft
  14. PSA Airlines: 139 aircraft
  15. Spirit Airlines: 136 aircraft
  16. Expressjet: 116 aircraft
  17. Allegiant Air: 91 aircraft
  18. Frontier Airlines: 90 aircraft
  19. Atlas Air 74 aircraft
  20. Horizon Air: 74 aircraft
  21. Piedmont: 60 aircraft
  22. Air Wisconsin: 64 aircraft
  23. Hawaiian Airlines: 56 aircraft
  24. Compass Airlines: 56 aircraft
  25. GoJet Airlines: 52 aircraft

The Legacy Carriers

American, Delta, and United are the three main legacy carriers in the United States. Combined, these three airlines operate over a staggering 2,500 aircraft.

American Airlines

The following is American’s active fleet using data from Airfleets.

American Airlines
American has over 325 Boeing 737 aircraft in its fleet. Photo: American Airlines
Delta Air Lines

Delta’s fleet, as per Airfleets, is the following:

  • 217 Boeing 737s
  • 127 Boeing 757s
  • 88 Boeing 717s
  • 87 Airbus A321s
  • 77 Boeing 767s
  • 70 MD-88s
  • 62 Airbus A320s
  • 57 Airbus A319s
  • 44 Airbus A330s (including A330-900neos)
  • 33 MD-90s
  • 21 Airbus A220s
  • 18 Boeing 777s
  • 13 Airbus A350s

A fair number of Delta’s fleet is getting quite old. As the world’s largest (and last) MD-90 operator, Delta has one of the oldest average fleet ages in the United States. However, Delta is replacing their aircraft with new, Airbus A220s and Airbus A321s.

50 years of Airbus - a reflection
Delta is the only legacy carrier to order the Airbus A220. Photo: Delta News Hub via Flickr
United Airlines

United operates the following aircraft as found in Airfleet’s database:

  • 343 Boeing 737s (including 14 grounded 737 MAX)
  • 99 Airbus A320s
  • 92 Boeing 777s
  • 75 Boeing 757s
  • 68 Airbus A319s
  • 53 Boeing 767s
  • 46 Boeing 787s

As you can see, United’s fleet is much more streamlined and skewed towards Boeing. Granted, United had its origins with Boeing. Although, recently, United has ordered some Airbus aircraft, including 45 Airbus A350-900s.

United 777
United operates a significant number of Boeing 777 aircraft. Photo: Tom Boon/Simple Flying

Southwest Airlines

Southwest Airlines is the world’s largest operator of the Boeing 737 with 753 of the type in service. Broken down, Southwest’s fleet is the following, according to Airfleets:

  • 512 Boeing 737-700
  • 208 Boeing 737-800
  • 34 Boeing 737 MAX 8 (currently grounded)
Southwest 737
Southwest is the world’s largest Boeing 737 operator. Photo: Southwest

The regional carriers

SkyWest, Republic, Envoy, Endeavor, Mesa, PSA, Expressjet, Horizon, Piedmont, Air Wisconsin, and Compass are regional carriers. Instead of operating their own flights, these carriers operate regional flights on behalf of other carriers. Regional arms of the legacy carriers are United Express, Delta Connection, and American Eagle.

Which US Airlines Operate The Largest Fleets?
An E175 regional jet operated by a Delta Connection partner. Photo: Delta Air Lines

A majority of their fleets are made up of Canadair Regional Jets and Embraer jets. Some, like Horizon, still operate turboprop Dash 8 aircraft.

Which US Airlines Operate The Largest Fleets?
A CRJ in SkyWest livery. Photo: SkyWest

Freight carriers

FedEx Express is the largest cargo airline by fleet in the United States. They operate the following aircraft:

  • 111 Boeing 757s
  • 75 Boeing 767s
  • 68 Airbus A300s
  • 56 MD-11s
  • 41 Boeing 777s
  • 33 ATRs
  • 29 DC-10s
  • 3 Airbus A310s

Cargo aircraft have a longer lifespan than passenger aircraft. Thus, FedEx Express still operates a number of older aircraft models that no longer fly passengers.

FedEx 767
A FedEx Express 767-300F. Photo: FedEx

UPS comes in as the next major cargo airline in the United States with these in their fleet:

  • 75 Boeing 757s
  • 64 Boeing 767s
  • 52 Airbus A300s
  • 37 MD-11s
  • 25 Boeing 747s
A UPS 747-8 freighter. Photo: UPS

The other carriers

Other passenger carriers, like Alaska, JetBlue, Spirit, Frontier, and Allegiant make up a chunk of the aircraft flying in the United States. However, these airlines are still growing and have not reached the size of the major US airlines.

That being said, they still comprise a sizeable fleet that enables them to expand into new markets. And, their newer aircraft offer additional fuel efficiency and less maintenance which helps save costs for the airline. Potentially, these airlines could shake things up with legacy carriers.

Frontier A321XLR
Frontier Airlines could shake things up with legacy carriers once they receive their A321XLRS. Photo: Airbus


Air travel demand to, from and within the United States is still a major market. The proof is that airlines keep growing and connecting new places. It will remain to be seen if American carriers keep up as Asian carriers also grow at an astonishing rate.